Investigations of biochemical defects in various forms of albinism and pigment defects in man and animals focus on the platelet and pigment defect in Hermansky-Pudlak syndrome, the kinetics and isolation of the various forms of tyrosinase, the uptake of tyrosine and copper by melanosomes and the role of cyclic nucleotides and prostaglandins in these systems. Anatomic and EEG studies focus on delineation of the extent of retinofugal decussation defect in various human types of albinos. Cell fusion studies of various mouse mutants seek control mechanisms for pigment formation combined with melanosome structural alterations and chemical control. Epidemiologic studies focus on the high incidence of dermal malignancy, chromosomal alterations and genetic types of albinism seen in high frequency in Enugu, Nigeria. BIBLIOGRAPHIC REFERENCES: King, R.A. and Witkop, C.J., Jr.: Detection of tyrosinase-negative oculocutaneous heterozygotes by hairbulb tyrosinase assay. Am. J. Hum. Genet. 29:164-168, 1977. Gerrard, J.M., Townsend, D., Stoddard, S., Witkop, C.J., Jr. and White, J.G.: The influence of prostaglandin G2 on platelet ultrastructure and platelet secretion. Am. J. Path. 86:99-122, 1977.